Option Explicit
Sub ChkIt()
'**************************************************************************
'ACHTUNG - Microsoft Scripting Runtime in VBA Projekt Verweise EINBINDEN!!!
'**************************************************************************
Dim dict As Dictionary
'**************************************************************************
'ACHTUNG - sonst knallts !!!
'**************************************************************************
'
'ab Zeile 3 mit Überschrift !!!
'
Dim oWs As Excel.Worksheet
Dim rngChk As Range, rngNew As Range
Dim arrChk As Variant, arrNew As Variant
Dim x As Long, y As Long
Dim sKey As String
'
Set dict = New Dictionary
dict.CompareMode = TextCompare
Set oWs = ThisWorkbook.ActiveSheet
With oWs
   Set rngChk = .Range("A3").CurrentRegion
   'Überschrift
   Set rngChk = rngChk.Offset(1, 0).Resize(rngChk.Rows.Count - 1, rngChk.Columns.Count)
   'Spalte B - H
   Set rngChk = Range(rngChk.Columns(2), rngChk.Columns(8))
   'letze Zeile = Prüfzeile
   Set rngNew = rngChk.Rows(rngChk.Rows.Count)
   'letze Zeile weg
   Set rngChk = rngChk.Resize(rngChk.Rows.Count - 1, rngChk.Columns.Count)
   'Datenfelder
   arrChk = rngChk: arrNew = rngNew
   'letze Zeile
   sKey = ""
   For y = LBound(arrNew, 2) To UBound(arrNew, 2)
      sKey = sKey & arrNew(1, y)
   Next y
   'ins dict
   dict.Add Key:=sKey, Item:=0
   'vergleichen
   For x = UBound(arrChk, 1) To LBound(arrChk, 1) Step -1
      sKey = ""
      'aktuelle Zeile
      For y = LBound(arrNew, 2) To UBound(arrNew, 2)
         sKey = sKey & arrChk(x, y)
      Next y
      ' = gespeicherte Zeile ?
      If dict.Exists(sKey) Then _
         Call MsgBox("in Zeile " & Format(x + 3, "#0"), vbExclamation, "Doppelter Eintrag")
   Next x
End With
Set oWs = Nothing
Set dict = Nothing
End Sub